1. Field of the Invention
The present invention relates to optical waveguide devices, and more particularly, to a pigtailing method between an optical waveguide device and an optical fiber array module.
2. Description of the Related Art
In general, optical waveguide devices are fabricated on a planar substrate using planar waveguide technology. The optical waveguide devices include an optical splitter, an optical coupler, an optical modulator, an optical switching element, an optical signal multiplexer, an equalizer and the like. In an effort to apply the optical waveguide devices to an optical communications system, various techniques have been studied, which may be generally divided into the fields of waveguide design, waveguide fabrication, waveguide packaging and environmental characteristic measurement of a waveguide device.
Among these techniques, waveguide packaging is an essential technique for allowing an optical waveguide device to take full advantage of its optical properties after it is fabricated. Particularly, a pigtailing process, that is a connecting process, between the optical waveguide device and an optical fiber array module is very important for enhancement of optical properties of the optical waveguide device.
A conventional pigtailing method uses an optical waveguide device having an optical waveguide formed on a substrate and which includes an input port and an output port on different surfaces of the device. A first optical fiber array module having a first optical fiber arranged on the module is attached to the input port and a second optical fiber array module having a second optical fiber arranged on the second module is attached to the output port. In the conventional pigtailing method between the optical waveguide device and the optical fiber array modules, the input port of the optical waveguide device and the first optical fiber array module are aligned and the first optical fiber array module is attached to the input port when the output level of the output port is highest. Then the output port of the optical waveguide device and the second optical fiber array module are aligned to then be attached to each other.
However, according to the above-described conventional pigtailing method between the optical waveguide device and the optical fiber array modules, since the input port and output port of the optical waveguide device exist on different planes, that is, on different surfaces of the substrate, the optical fiber array modules must be separately attached to the two planes. Thus, in the pigtailing process between an optical waveguide device and an optical fiber, the step necessary for attachment of an optical fiber array module must be repeated for an input port and an output port, thus being performed twice overall. As a result, the conventional pigtailing method between an optical waveguide device and an optical fiber involves considerable cost.
Based on my observation of the art, then, I have discovered that what is needed is an improved pigtailing method. Specifically, a method is needed in which the optical waveguide device and the optical fiber array are coupled in a single step.